Radioactivity of granites: truth or myth

Increasingly, buyers who are engaged in the repair or construction of a house put the issue of material safety in the first place, since the main global trend in our time is the maximum naturalness and environmental friendliness of materials.
Today there is a lot of talk about the environmental friendliness and radioactivity of granite, and whether this material is suitable for indoor use. This is due to some prejudices and rumors in relation to granite, in connection with which people have a question, how safe is granite, and whether it is worth putting countertops in the kitchen or window sills in living rooms from it. These rumors need to be dealt with, but first, you need to clarify what radioactivity is and what classes it has.

Radioactivity

Radioactivity is radiation, the emission of rays by any body, such as the Sun (solar radiation) or another source. Radioactivity can be natural or artificial. Natural radioactivity has existed for billions of years and is present literally everywhere. Radioactive materials have entered the composition of the Earth since its very birth, therefore, it is obvious that any person, as an element of this Earth, is slightly radioactive: in the tissues of the human body, one of the main sources of natural radiation is potassium-40 and rubidium-87. Artificial radioactivity is the result of human activity. This includes all materials and processes created by man – X-rays, the extraction of oil, gas, and other fossil fuels, the use of phosphate fertilizers, the extraction and processing of ores, nuclear weapons testing, nuclear power and industry.

Classification of radioactivity

The classification of the radioactivity of building materials is presented in Becquerels per kg (Bq / kg). Becquerel is a unit of measurement for the activity of a radioactive source. One becquerel is defined as the activity of a source in which, on average, one radioactive decay occurs per second.

Building materials containing radioactive substances are divided into classes of use (the higher the class, the more radioactivity):

1st class – radioactivity content no more than 370 Bq / kg. Materials of this class can be used in all types of construction without restrictions;

Class II – radioactivity no more than 740 Bq / kg. Materials belonging to this class can be used for external cladding and finishing, for the construction of industrial structures and for road construction within settlements;

III class – radioactivity no more than 1500 Bq / kg. Materials for road construction, underground structures and communications, and for the construction of other objects, the time spent by people in which is no more than 50% of the working day.

In our company we offer for sale only safe natural granites of the first and second class. Class “A” corresponds to radiation up to 370 bq / kg, but our main products have a lower specific activity:

1. Gabbro-diabase of the Drugoretskoye deposit – 48 bq / kg;
2. Garnet amphibolite from the Nigrozero deposit – 40 bq / kg;
3. Green pyroxenite from the Buntina Sopka deposit – 28 bq / kg;
4. Granosyenite of the Baltic deposit – 305 bq / kg;

That is, in the bulk, granites belonging to the first class are used for the manufacture of kitchen countertops (all types of buildings without restrictions). The radiation content in granite is so low that it cannot compete with other natural sources of radiation. It is also necessary to take into account the short duration of human interaction with this material.

And, of course, one of the main factors “against” the concept of radioactivity of granite is the growing competition. Manufacturers of piece and composite substitute goods, as growth slows and their own market becomes saturated, must constantly think about maintaining the growth rate. The “native” market is no longer so attractive, and this fact makes them enter the field of producers of natural materials. That is why, from time to time, there are such “stuffing” about the great harm of granite in human life.